Among the conventionally-known front vehicle body structures are ones employed in vehicles where an engine is oriented transversely in an engine compartment. In the front vehicle body structures of that type, left and right side regions of a dashboard panel, which functions as a partition wall between the engine compartment and the passenger compartment, are each formed in an arch shape to provide a wheel arch section; parts of these left and right wheel arch sections arcuately project into left and right side regions of the passenger compartment, in order to not interfere with steering movement of tires of left and right road wheels.
One example of such front vehicle body structures is disclosed in Japanese Patent Application Laid-Open Publication No. 2004-67082 (JP 2004-067082 A), where a front section of the passenger compartment is surrounded by pipe members in order to transmit a load, applied from front side frames, to left and right front pillars (commonly known as A-pillars) and left and right side sills. More specifically, the front vehicle body structure disclosed in JP 2004-67082 A includes: the dashboard panel (end wall) disposed between the engine compartment and the passenger compartment; left and right front side members connected to the dashboard panel; left and right side sills disposed on left and right outer sides of the vehicle body; left and right front pillars (A-pillars) projecting upward from the left and right side sills; and a vehicle body floor extending from the dashboard panel and spanning between the left and right side sills.
Load input from the engine compartment to the passenger compartment (cabin) comprises one from upper members and one from lower side frames, and these input is primarily due to vibration of front wheels transmitted via component parts of suspensions, such as dampers. For a load input via the front side frame, there is a need to increase rigidity of the dashboard because the dashboard panel functions as a reacting point or surface against such a load input.
However, if a reinforcing member, such as a cross member or pipe member, is provided outside the wheel arch sections of the dashboard panel in the front vehicle body structure, the reinforcing member would interfere with the front wheels (tires) and thus create layout limitations in the front section of the vehicle body. Thus, it is difficult to provide such a reinforcing member outside the wheel arch sections. If, on the other hand, such a reinforcing member is provided inside the passenger compartment, the space inside the passenger compartment would be sacrificed.